The objectives of this research are: 1) To prepare fluorescent derivatives of ACTH for the localization of hormone receptors in adrenal cells; 2) To prepare chemically reactive or toxic hormone derivatives which will have specific inhibitory or chemotherapeutic effects on the adrenal; 3) To investigate the role of calcium-dependent regulator protein in mediating the action of ACTH and controlling adenylate cyclase activity; 4) To investigate the catalytic mechanism of solubilized adenylate cyclase by kinetic measurements of the forward and reversed reactions; and 5) To define the nature of the abnormalities in adrenal tumor cell lines which are unresponsive to ACTH.